Transistors are widely used as switches for switching electrical currents supplied to loads. In many applications it is desired to measure the current through the load. Several different concepts are known for measuring a current through a transistor and a load, respectively.
According to a first concept, a shunt resistor is connected in series with the transistor, and a voltage across the resistor is measured. This voltage, in accordance with Ohm's law, is proportional to the current through the transistor. The shunt resistor, however, causes power losses.
According to a further concept, a measurement transistor is provided that is operated in the same operation point as the load transistor connected in series with the load, so that a measurement current through the measurement transistor is proportional to a load current through the load. Although the load transistor and the measurement transistor can be configured such that the measurement current is much smaller than the load current, losses may occur in connection with the current measurement.
There is a need for a semiconductor arrangement that includes a semiconductor device configured to be connected in series with a load and a measurement device, wherein the measurement device has very low losses and can be integrated with the semiconductor device in a common semiconductor body.